Re: [Powertop] segfault on Sheevaplug (ARM Kirkwood)

On (05/20/12 04:01), Rui DaCosta wrote: > Thanks, > this has gotten past the issue. I now get: > PowerTOP v2.0 needs the kernel to support the 'perf' subsystem > as well as support for trace points in the kernel: > > CONFIG_PERF_EVENTS=y > CONFIG_PERF_COUNTERS=y > CONFIG_TRACEPOINTS=y > CONFIG_TRACING=y > > all these except CONFIG_PERF_COUNTERS are already set, so i'll need to see > if i can get a kernel built with that option on. > > Will this patch make it into trunk? > Well, it depends. The patch itself is quite innocent -- assuming default number of processors being 1 instead of -1 will not do any harm. Of course, such default value could be considered as debugging friendly, yet segfault is still no good. We'll see what project owners think about that.

-ss > Many thanks. > > ────────────────────────────────────────────────────────────────────────── > > From: Sergey Senozhatsky&lt;sergey.senozhatsky(a)gmail.com&gt; > To: Rui DaCosta&lt;ruidc(a)yahoo.com&gt; > Cc: Arjan van de Ven&lt;arjan(a)linux.intel.com&gt;; Chris Ferron > <chris.e.ferron(a)linux.intel.com&gt;; powertop(a)lists.01.org > Sent: Sunday, 20 May 2012, 11:34 > Subject: Re: [Powertop] segfault on Sheevaplug (ARM Kirkwood) > On (05/20/12 02:19), Rui DaCosta wrote: > > Sure and thanks, > > (v1.13 worked fine btw) > > Processor : Feroceon 88FR131 rev 1 (v5l) > > BogoMIPS : 1191.11 > > Features : swp half thumb fastmult edsp > > CPU implementer : 0x56 > > CPU architecture: 5TE > > CPU variant : 0x2 > > CPU part : 0x131 > > CPU revision : 1 > > > > Hardware : Marvell SheevaPlug Reference Board > > Revision : 0000 > > Serial : 0000000000000000 > > > > > > Thanks, > > Well, that's the problem. Current cpu info parser doesn't understand your > cpuinfo format. It awaits for sane values on special places. For example, > word > "processor" should be followed by a number, not model name. > > processor : 2 > vendor_id : GenuineIntel > cpu family : 6 > model : 37 > bogomips : 4522.66 > > while cpuinfo on your system is totally different. > > the following is untested patch (I'm a bit skeptical) plus I don't have > ARM device for testing. > > --- > > src/cpu/cpu.cpp | 26 ++++++++++++++------------ > 1 file changed, 14 insertions(+), 12 deletions(-) > > diff --git a/src/cpu/cpu.cpp b/src/cpu/cpu.cpp > index 09d4a2d..143e18c 100644 > --- a/src/cpu/cpu.cpp > +++ b/src/cpu/cpu.cpp > @@ -225,7 +225,7 @@ void enumerate_cpus(void) > ifstream file; > char line[1024]; > > - int number = -1; > + int number = 1; > char vendor[128]; > int family = 0; > int model = 0; > @@ -236,7 +236,6 @@ void enumerate_cpus(void) > return; > > while (file) { > - > file.getline(line, sizeof(line)); > if (strncmp(line, "vendor_id\t",10) == 0) { > char *c; > @@ -247,42 +246,45 @@ void enumerate_cpus(void) > c++; > strncpy(vendor,c, 127); > } > - } > - if (strncmp(line, "processor\t",10) == 0) { > + } else if (strncmp(line, "processor\t",10) == 0) { > char *c; > c = strchr(line, ':'); > if (c) { > c++; > number = strtoull(c, NULL, 10); > } > - } > - if (strncmp(line, "cpu family\t",11) == 0) { > + } else if (strncmp(line, "Processor\t",10) == 0) { > + char *c; > + c = strchr(line, ':'); > + if (c) { > + c++; > + if (*c == ' ') > + c++; > + strncpy(vendor, c, 127); > + } > + } else if (strncmp(line, "cpu family\t",11) == 0) { > char *c; > c = strchr(line, ':'); > if (c) { > c++; > family = strtoull(c, NULL, 10); > } > - } > - if (strncmp(line, "model\t",6) == 0) { > + } else if (strncmp(line, "model\t",6) == 0) { > char *c; > c = strchr(line, ':'); > if (c) { > c++; > model = strtoull(c, NULL, 10); > } > - } > - if (strncasecmp(line, "bogomips\t", 9) == 0) { > + } else if (strncasecmp(line, "bogomips\t", 9) == 0) { > handle_one_cpu(number, vendor, family, model); > set_max_cpu(number); > } > } > > - > file.close(); > > perf_events = new perf_power_bundle(); > - > if (!perf_events->add_event("power:cpu_idle")){ > perf_events->add_event("power:power_start"); > perf_events->add_event("power:power_end");